Add initial support for the Synopsys DesignWare HDMI RX
Controller Driver used by Rockchip RK3588. The driver
supports:
 - HDMI 1.4b and 2.0 modes (HDMI 4k@60Hz)
 - RGB888, YUV422, YUV444 and YCC420 pixel formats
 - CEC
 - EDID configuration

The hardware also has Audio and HDCP capabilities, but these are
not yet supported by the driver.

Signed-off-by: Dingxian Wen <shawn.wen@rock-chips.com>
Co-developed-by: Shreeya Patel <shreeya.patel@collabora.com>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>